Passive cooling of cutaneous and subcutaneous tissues using phase changing materials: feasibility study using a numerical model.

In many dermatological applications, lowering the temperature of skin and maintaining specific temperatures for extended periods of time are fundamental requirements for treatment; for example, in targeting adipose tissue and managing cutaneous pain. In this work, we investigate the feasibility of using phase changing materials (PCMs) as an alternative passive, open-loop, heat extraction method for cooling cutaneous and subcutaneous tissues. We used a finite difference parametric approach to model the spatial and temporal progression of the heat transferred from the skin to a PCM in contact with the skin surface. We modelled the thermal performance of different PCMs, including different thicknesses. In addition, we used our model to propose application strategies. Numerical simulations demonstrate the feasibility of using PCMs for extracting heat from the skin and upper fat layers, inducing and maintaining similar temperatures as those induced by active closed-loop cooling with a cold plate. In terms of development, the critical design parameters are the temperature range of solidification of the material, the thickness of the material, and the rate of melting. Our study suggests that PCM-based devices may offer an alternative skin and adipose tissue cooling method that is simple to implement and use.